Display device

ABSTRACT

A display device includes a display panel, a data driver which transmits a data voltage to the display panel, a first flexible printed circuit board attached to the display panel and including an input side wiring electrically connected to the data driver, a first printed circuit board (PCB) electrically connected to the input side wiring to transmit a high-speed driving signal to the data driver, and a metal tape overlapping the input side wiring in a plan view and attached on the first flexible printed circuit board, where a part of the metal tape overlapping the input side wiring in the plan view defines an opening.

This application claims priority to Korean Patent Application No.10-2020-0027044, filed on Mar. 4, 2020, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND 1. Field

The present disclosure relates to a display device, and in detailrelates to a driving chip for a display device and a tape coveringperipheral wiring thereof.

2. Description of the Related Art

A display device of various types is used, and typically, this may be aliquid crystal display or an organic light emitting device.

The liquid crystal display includes a backlight unit, and is a displaydevice that blocks or transmits light emitted from the backlight unit todisplay an image.

The organic light emitting device is a display device that has aself-luminous characteristic, and unlike a liquid crystal display, doesnot require a separate light source.

The display device is manufactured in various sizes, where a smalldisplay device is representatively used for a mobile phone, and atelevision and a monitor are typical examples of a large display device.

The size of the large display device is getting very large. The largestdisplay device that was previously sold is 50 inches, but more than a70-inch display device is currently sold, and a very large displaydevice of 100 inches is also on the market.

Such a display device is driven through a driving chip, and the drivingchip receives signals through a high-speed signal wire, converts thesignal, and outputs the converted signal to a display panel.

SUMMARY

Exemplary embodiments provide a display device for improvingtransmission performance by considering an impedance characteristic onsignals transmitted to a driving chip.

A display device according to an exemplary embodiment includes a displaypanel; a data driver which transmits a data voltage to the displaypanel; a first flexible printed circuit board attached to the displaypanel and including an input side wiring electrically connected to thedata driver; a first printed circuit board (“PCB”) electricallyconnected to the input side wiring to transmit a high-speed drivingsignal to the data driver; and a metal tape overlapping the input sidewiring in a plan view and attached on the first flexible printed circuitboard, where a part of the metal tape overlapping the input side wiringin the plan view defines an opening.

The opening may be defined in a wiring overlapping part of the metaltape where the metal tape overlaps the input side wiring.

The wiring overlapping part may extend from the data driver toward aninput side pad disposed at an end of the input side wiring.

The metal tape may further include a heat discharge part covering thedata driver.

The metal tape may further include an adhesion part which helpsattachment on the first flexible printed circuit board.

A width of the heat discharge part and a width of the adhesion part maybe different from each other.

The width of the heat discharge part and the width of the adhesion partmay be the same.

The metal tape may have a plate structure.

The opening may be provided in plural, and the wiring overlapping partmay further include a linear structure disposed along an outer peripheryof the wiring overlapping part.

A display device according to an exemplary embodiment includes a displaypanel; a data driver which transmits a data voltage to the displaypanel; a first flexible printed circuit board attached to the displaypanel and including an input side wiring electrically connected to thedata driver; a first printed circuit board (PCB) electrically connectedto the input side wiring and transmitting a high-speed driving signal tothe data driver; and a metal tape overlapping the input side wiring in aplan view and attached on the first flexible printed circuit board,where the metal tape includes a heat discharge part overlapping the datadriver in the plan view and disposed in an extending direction of thedata driver and a wiring overlapping part disposed in a directionperpendicular to the extending direction of the data driver.

The metal tape may include a metal layer and an adhesive layer, and theadhesive layer may be disposed on the entire surface of the metal tape.

The metal tape may further include an adhesion part which helpsattachment on the first flexible printed circuit board, and the heatdischarge part, the wiring overlapping part and the adhesion part may beseparated from each other in the plan view.

A width of the heat discharge part and a width of the adhesion part maybe different from each other.

The width of the heat discharge part and the width of the adhesion partmay be the same.

The wiring overlapping part may be separated from an input side paddisposed at an end of the input side wiring by a predetermined distancein the plan view.

The wiring overlapping part may be in contact with the input side paddisposed at the end of the input side wiring in the plan view.

The heat discharge part and the wiring overlapping part may be separatedwith a predetermined interval, and the separated heat discharge part andwiring overlapping part may be connected to each other by an adhesivecontained in the metal tape.

The wiring overlapping part may define a plurality of openings and mayhave a linear structure disposed along an outer periphery of the wiringoverlapping part.

The display device may further include a timing controller whichprocesses an image signal applied from the outside and transmits theprocessed image signal to the data driver; a second printed circuitboard (PCB) in which the timing controller is disposed; and a secondflexible printed circuit board connecting the second printed circuitboard (PCB) and the first printed circuit board (PCB).

The first printed circuit board (PCB) may be provided in plural, and thefirst printed circuit boards (PCB) may include a first printed circuitboard (PCB) connected to the second flexible printed circuit board and afirst printed circuit board (PCB) which is not connected to the secondflexible printed circuit board, and the display device may furtherinclude a third flexible printed circuit board which connects the firstprinted circuit board (PCB) which is not connected to the secondflexible printed circuit board and the first printed circuit board (PCB)connected to the second flexible printed circuit board.

According to exemplary embodiments, the impedance of the signal has areduced difference or is set less than a predetermined range by the tapecovering the wiring input to the driving chip and including the metalsuch that transmission performance of the signal to the driving chip isimproved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a display device according to anexemplary embodiment.

FIG. 2 is a top plan view showing a first flexible printed circuit boardand surroundings thereof according to an exemplary embodiment.

FIG. 3 is an exploded perspective view showing a first flexible printedcircuit board and surroundings thereof according to an exemplaryembodiment.

FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 2.

FIG. 5 is a graph showing an impedance characteristic of a signaltransmitted to a driving chip in a display device according to anexemplary embodiment.

FIGS. 6A and 6B are views showing an electric field characteristic on across-section of a first flexible printed circuit board according to acomparative example and an exemplary embodiment.

FIG. 7 is an equivalent circuit diagram for a transmission path of adisplay device according to an exemplary embodiment of FIG. 1.

FIG. 8 is an eye diagram in an input side of a data driver according toan exemplary embodiment.

FIG. 9 is an eye diagram in an input side of a data driver according toa comparative example.

FIG. 10 is an enlarged cross-sectional view of a metal tape according toan exemplary embodiment.

FIG. 11 and FIG. 12 are top plan views of a metal tape according to anexemplary embodiment.

FIG. 13 is a top plan view of a first flexible printed circuit boardincluding a metal tape according to an exemplary embodiment.

FIG. 14 is a top plan view of a first flexible printed circuit boardincluding a metal tape according to an exemplary embodiment.

FIG. 15 is a top plan view of a first flexible printed circuit boardincluding a metal tape according to an exemplary embodiment.

FIG. 16 is a cross-sectional view taken along line XVI-XVI of FIG. 15.

FIG. 17 to FIG. 25 are top plan views of a first flexible printedcircuit board including a metal tape according to an exemplaryembodiment.

DETAILED DESCRIPTION

The present invention will be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. As those skilled in the art would realize,the described embodiments may be modified in various different ways, allwithout departing from the spirit or scope of the present invention.

The drawings and description are to be regarded as illustrative innature and not restrictive, and like reference numerals designate likeelements throughout the specification.

Further, in the drawings, a size and thickness of each element arearbitrarily represented for better understanding and ease ofdescription, and the present invention is not limited thereto. In thedrawings, the thicknesses of layers, films, panels, regions, etc., areexaggerated for clarity. In the drawings, for understanding and ease ofdescription, the thicknesses of some layers and areas are exaggerated.

It will be understood that when an element such as a layer, film,region, or substrate is referred to as being “on” another element, itcan be directly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” another element, there are no intervening elements present. Further,in the specification, the word “on” or “above” means positioned on orbelow the object portion, and does not necessarily mean positioned onthe upper side of the object portion based on a gravitational direction.

In addition, unless explicitly described to the contrary, the word“comprise” and variations such as “comprises” or “comprising” will beunderstood to imply the inclusion of stated elements but not theexclusion of any other elements.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, “a first element,” “component,” “region,” “layer” or“section” discussed below could be termed a second element, component,region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “At least one” is not to be construed as limiting “a” or“an.” “Or” means “and/or.” As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.

Further, throughout the specification, the word “on a plane” meansviewing a target portion from the top, and the word “on a cross-section”means viewing a cross-section formed by vertically cutting a targetportion from the side.

Hereinafter, a display device is entirely described with reference toFIG. 1.

FIG. 1 is a schematic diagram of a display device according to anexemplary embodiment.

A display device according to an exemplary embodiment may include adisplay panel 100, flexible printed circuit boards 200, 310, and 410,printed circuit boards (PCB) 300 and 400, a data driver 250, and atiming controller 450.

The display panel 100 according to the present exemplary embodimentincludes a display area 110 in which a plurality of pixels PX aredisposed, and a driving unit may be disposed outside the display area110 by the same process as that of forming the pixels PX. The displaypanel 100 may be a liquid crystal panel including a liquid crystal, or alight emitting display panel including a light-emitting element. Inaddition, the display panel 100 of the exemplary embodiment shown inFIG. 1 may be a medium to large display panel.

The plurality of pixels PX included in the display panel 100 may becontrolled by various control signals including a scan signal and a datavoltage, and may receive a power supply voltage having a constantvoltage.

In the liquid crystal panel, the plurality of pixels PX receives thedata voltage and the scan signal. The data voltage applied to the pixelPX forms an electric field with a common voltage, and an arrangementdirection of liquid crystal molecules is determined depending on theelectric field. The liquid crystal panel may further include anadditional light unit, and a luminance is expressed while a ratio atwhich light provided from the light unit is controlled by a polarizer byreceiving a phase difference according to the arrangement direction ofthe liquid crystal molecules.

The light emitting display panel may be an organic light emitting panelincluding an organic emission layer or an inorganic light emittingdisplay panel including an inorganic emission layer. In the lightemitting display panel, the plurality of pixels PX receives the datavoltage and at least one scan signal, and may also receive the drivingvoltage and a low driving voltage as power supply voltages. Also, alight emitting signal may be additionally received. In the organic lightemitting panel, an output current of the driving transistor isdetermined based on the data voltage, and light is emitted while theoutput current flows to the organic light emitting diode. The luminanceof light emitted by the organic light emitting diode is determinedaccording to the magnitude of the current flowing through the organiclight emitting diode.

Although not shown in FIG. 1, the display panel 100 includes a scandriver generating the scan signal. The scan driver is disposed outsidethe display area 110, and may be formed together through the process forforming the plurality of pixels PX.

The light emitting signal used in the organic light emitting device isalso provided from a separate driver conforming to the scan driver, andthe driver providing the light emitting signal may also be formedtogether through the process of forming the plurality of pixels PX insome regions outside the display area 110.

In an exemplary embodiment, the data driver 250 (hereinafter referred toas a data driving chip) applying the data voltage is disposed on a firstflexible printed circuit board 200 (hereinafter referred to as aflexible printed circuit board for the data driving chip), and thetiming controller 450 is disposed on a second printed circuit board(PCB) 400 (hereinafter; referred to as a printed circuit board (PCB) fora timing controller).

The timing controller 450 generates image data and a control signalbased on the image signal input from the outside, and the data driver250 receives the image data from the timing controller 450, changes theimage data into the data voltage to be applied to the pixel, andtransmits the data voltage to the pixel PX.

The signal outputted from the timing controller 450 is transmitted tothe first printed circuit board (PCB) 300 through the second printedcircuit board (PCB) 400 and the second flexible printed circuit board410.

In the exemplary embodiment of FIG. 1, four first printed circuit boards(PCB) 300 are formed and are disposed in pairs of two. The paired twofirst printed circuit boards (PCB) 300 are electrically connected toeach other by a third flexible printed circuit board 310 (also referredto as a flexible printed circuit board for a connection). As a result,if the signal outputted from the timing controller 450 is applied to thefirst printed circuit board (PCB) 300 through the second printed circuitboard (PCB) 400 and the second flexible printed circuit board 410, thesignal is transmitted to the second first printed circuit board (PCB)300 through the third flexible printed circuit board 310. When the firstprinted circuit boards (PCB) 300 are classified based on the connectionrelationship, the first printed circuit boards (PCB) 300 are classifiedbased on whether the first printed circuit board (PCB) 300 is directlyconnected with or not directly connected with the second flexibleprinted circuit board 410.

The first printed circuit board (PCB) 300 that is directly connected tothe second flexible printed circuit board 410 receives the signaloutputted from the timing controller 450 through the second printedcircuit board (PCB) 400 and the second flexible printed circuit board410.

The first printed circuit board (PCB) 300 that is not directly connectedto the second flexible printed circuit board 410 is connected to thefirst printed circuit board (PCB) 300 that is directly connected to thesecond flexible printed circuit board 410 through the third flexibleprinted circuit board 310. As a result, the first printed circuit board(PCB) 300 that is not directly connected to the second flexible printedcircuit board 410 receives the signal outputted from the timingcontroller 450 through the third flexible printed circuit board 310.Here, the third flexible printed circuit board 310 receives the signaloutputted from the timing controller 450 through the second printedcircuit board (PCB) 400, the second flexible printed circuit board 410,and the adjacent first printed circuit board (PCB) 300.

The signal transmitted to the first flexible printed circuit board 200through the first printed circuit board (PCB) 300 may be processed inthe data driver 250 and transmitted to the display panel 100. However,some of the signals transmitted to the first flexible printed circuitboard 200 may be transmitted to the display panel 100 without passingthrough the data driver 250.

The control signal (i.e., a data control signal) for the data driver 250and an image signal among the control signals outputted from the timingcontroller 450 are transmitted to the data driver 250 disposed in thefirst flexible printed circuit board 200 and converted into the datavoltage, and then the data voltage is transmitted to the display panel100.

The scan driver control signal (i.e., a scan control signal) among thecontrol signals outputted from the timing controller 450 is transmittedto the scan driver in the display panel 100 through the second printedcircuit board (PCB) 400, the second flexible printed circuit board 410,the first printed circuit board (PCB) 300, and the first flexibleprinted circuit board 200 without passing through the data driver 250.

In the exemplary embodiment of FIG. 1, a total of sixteen first flexibleprinted circuit boards 200 are included, and a total of sixteen datadrivers 250 are included. The data driver 250 may be attached on thefirst printed circuit board (PCB) 300 in a form of an IC chip.

Also, the timing controller 450 may be attached on the second printedcircuit board (PCB) 400 in the form of an IC chip. The second printedcircuit board (PCB) 400 may further include a power supply voltagegenerator for generating a power supply voltage.

The display panel 100, the flexible printed circuit boards 200, 310, and410, and the printed circuit boards (PCB) 300 and 400 are attached by ananisotropic conductive film (“ACF”) and electrically connected to eachother.

In an exemplary embodiment, the display device may include only oneflexible printed circuit board and one printed circuit board (PCB). Inthis case, the timing controller 450 may be disposed on the printedcircuit board (PCB), and the data driver 250 may be disposed on theflexible printed circuit board, or may be attached and formed on oneside region of the display panel 100. Also, in another exemplaryembodiment, the flexible printed circuit board or the printed circuitboard (PCB) may be additionally included while basically including oneflexible printed circuit board and one printed circuit board (PCB).

Hereinafter, the first flexible printed circuit board and itssurrounding structures are described in detail with reference to FIG. 2to FIG. 4.

FIG. 2 is a top plan view showing a first flexible printed circuit board200 and surroundings thereof according to an exemplary embodiment, FIG.3 is an exploded perspective view showing a first flexible printedcircuit board and surroundings thereof according to an exemplaryembodiment, and FIG. 4 is a cross-sectional view taken along line IV-IVof FIG. 2.

First, FIG. 2 and FIG. 3 are described.

FIG. 2 shows the part of the display panel 100 and the part of the firstprinted circuit board (PCB) 300 with the first flexible printed circuitboard 200 as a main portion, and FIG. 3 illustrates the structure of thefirst flexible printed circuit board 200 in a disassembled state.

Input side wiring 225 connected to the data driver 250 is disposed onthe first flexible printed circuit board 200. The part among the wiringinput to the data driver 250 is omitted, and wiring (output side wiring)outputted from the data driver 250 to the display panel 100 is alsoomitted in FIGS. 2 and 3.

An extended input side pad 220 is disposed at the end of the input sidewiring 225 connected to the data driver 250. The input side pad 220 iselectrically connected to a pad 320 disposed at the end of high-speeddriving wiring 325 disposed on the first printed circuit board (PCB)300. As a result, the input side wiring 225 connected to the data driver250 is electrically connected to the high-speed driving wiring 325disposed on the first printed circuit board (PCB) 300, and may have adifferential pair transmitting the signal through a pair of wirings likethe high-speed driving wiring 325. The input side pad 220 and the pad320 of the first printed circuit board (PCB) 300 are electricallyconnected by the anisotropic conductive material (ACF).

The first flexible printed circuit board 200 further includes a metaltape 230 covering the data driver 250 attached in the form of the chip.

The metal tape 230 includes an adhesion part 231, a heat discharge part232 overlapping the data driver 250, and a wiring overlapping part 233overlapping the input side wiring 225.

The heat discharge part 232 of the metal tape 230 according to anexemplary embodiment of FIG. 2 absorbs the heat of the data driver 250to discharge the heat generated while the data driver 250 is operated,transmits the absorbed heat to the adhesion part 231 and/or the wiringoverlapping part 233, and resultantly the heat of the data driver 250 istransferred to the first flexible printed circuit board 200 such thatthe heat is reduced. The heat discharge part 232 according to anexemplary embodiment of FIG. 2 has a structure of which the width W2 isnarrower compared with the width W1 of the adhesion part 231.

The adhesion part 231 may be disposed at the right/left ends of the heatdischarge part 232 and partially overlap the data driver 250. However,it entirely overlaps the first flexible printed circuit board 200 suchthat the entire metal tape 230 is attached to the first flexible printedcircuit board 200. The width of the adhesion part 231 is wide enoughsuch that the metal tape 230 does not fall, and the heat is welldischarged to the first flexible printed circuit board 200. Theexemplary embodiment of FIG. 2 has a structure in which the width of theadhesion part 231 is larger than the width of the heat discharge part232.

The wiring overlapping part 233 is disposed extending from the heatdischarge part 232 toward the upper part of the input side wiring 225,and has an overlapped structure in a plan view such that the input sidewiring 225 to which the high-speed signal is applied is disposed inside.The wiring overlapping part 233 may eliminate or reduce impedancedifference occurring on the high-speed signal transmitting through theinput side wiring 225. According to an exemplary embodiment, the size ofthe wiring overlapping part 233 may be set so as to match the impedance.however, the impedance does not necessarily match, and the difference inimpedance may be reduced to reduce the loss in the signal transmissionperformance. As a result, the capacitance is formed between the metallayer of the input overlap wiring part 233 and the input side wiring225, thereby reducing a loss due to an impedance difference that mayoccur when the high-speed signal is transmitted and reducing theimpedance difference with a level equivalent to impedance matching.

The wiring overlapping part 233 extends from the heat discharge part 232and may be extended to a position close to the input side pad 220. Inthe exemplary embodiment of FIG. 2, a distance between the input sidepad 220 and the wiring overlapping part 233 in a plan view is indicatedby g, and the g is in a range including 0. As the value of g increases,the capacitance between the metal layer of the wiring overlapping part233 and the input side wiring 225 decreases. According to the change ofthe capacitance, the value g may be set for the smallest loss of thecapacitance. In another exemplary embodiment, the value of g may have anegative value, such that the wiring overlapping part 233 may bedisposed to overlap with the input side pad 220 in a plan view, In stillanother exemplary embodiment, the wiring overlapping part 233 may passthrough the input side pad 220 and extend to the outside of the firstflexible printed circuit board 200. The wiring overlapping part 233 hasits maximum length in a case of passing through the input side pad 220and extending to the outside of the first flexible printed circuit board200, and the wiring overlapping part 233 may have a shorter length thanthis in general. The wiring overlapping part 233 may be disposed to havean appropriate length by considering a parasitic capacitance with otheroverlapped wiring and the impedance characteristic. In addition, whenthe wiring overlapping part 233 overlaps the input side pad 220, theinput side pad 220 may be disposed such that there is no problem inbeing electrically connected to the pad 320 disposed on the firstprinted circuit board (PCB) 300.

That is, the wiring overlapping part 233 may have various sizes andshapes according to an exemplary embodiment. The minimum width of thewiring overlapping part 233 is a case that the wiring overlapping part233 has the same width as the width of the input side wiring 225 towhich the high-speed signal is applied, and in this case, an opening isdefined at the part between two pairs of input side wirings 225 suchthat the wiring overlapping part 233 is not disposed on the part betweentwo pairs of input side wirings 225. The wiring overlapping part 233 maybe wider than the minimum width in general, and may be disposed to havean appropriate width by considering the parasitic capacitance and theimpedance characteristics with other overlapped wiring.

According to an exemplary embodiment, the wiring overlapping part 233may define the opening of various structures, and some exemplaryembodiments are shown in FIG. 14, FIG. 18, FIG. 21, and FIG. 24.

Also, the wiring overlapping part 233 does not overlap the output sidewiring from the data driver 250 to the display panel 100 such that thesignal delay is not generated by the parasitic capacitance in the wiringtransmitting the signal to the display panel 100. In addition, the heatdischarge part 232 also does not have the part overlapping the outputside wiring except for the part required during the heat discharge tominimize the overlapping area with the output side wiring, therebyhaving the structure reducing the problem due to the parasiticcapacitance.

FIG. 4 shows the cross-sectional view taken along line IV-IV of FIG. 2,and the cross-sectional structure of the first flexible printed circuitboard 200 is shown. In the first flexible printed circuit board 200, ina cross-sectional view, a film layer 211, input side wiring 225, aninsulating layer 212, an adhesive layer 213, and a wiring overlappingpart 233 of the metal tape 230 are sequentially disposed from a bottom.In FIG. 4, at a position of the cross-section, the wiring overlappingpart 233 is only shown among the metal tape 230, and the input sidewiring 225 is only shown among the various wirings, the part of theother metal tape 230 is disposed in the same position as the wiringoverlapping part 233, and the various other wirings are disposed in thesame position as the input side wiring 225.

The film layer 211 is formed of or includes a material having a flexiblecharacteristic such as a polyimide, and various wirings including theinput side wiring 225 made of or including a metal are formed thereon.An insulating layer 212 is disposed on the various wirings including theinput side wiring 225, and an adhesive layer 213 is disposed thereonsuch that the wiring overlapping part 233 of the metal tape 230 isattached thereon.

In the present exemplary embodiment, the adhesive layer 213 is attachedto the first flexible printed circuit board 200, the wiring overlappingpart 233 of the metal tape 230 is attached to the adhesive layer 213,and the width of the adhesive layer 213 is larger than the width of thewiring overlapping part 233 of the metal tape 230. However, in anexemplary embodiment, the adhesive layer 213 may be disposed at theentire bottom surface of the metal tape 230 to have the same width asthe cross-section of the wiring overlapping part 233 of the metal tape230. (Referring to FIG. 16)

As shown in FIG. 4, the wiring overlapping part 233 overlaps the inputside wiring 225 in the vertical direction, thereby configuring theparasitic capacitor along with the adhesive layer 213 and the insulatinglayer 212 disposed therebetween. The impedance difference on thetransmission path is reduced by the capacitance of the parasiticcapacitor such that the signal transmission performance may be preventedfrom being deteriorated due to the impedance difference.

In addition, in FIG. 4, the parasitic capacitance between the wiringoverlapping part 233 and the input side wiring 225 is also affected bythe distance between them. As a result, it is also possible to modifythe thickness of the adhesive layer 213 and/or the insulating layer 212disposed therebetween to reduce the difference in the impedance on thetransmission line.

The effect of reducing the impedance difference may be shown through agraph of FIG. 5.

FIG. 5 is a graph showing an impedance characteristic of a signaltransmitted to a driving chip in a display device according to anexemplary embodiment.

FIG. 5 shows a change of an impedance (ohm: Ω) value (y axis) dependingon time (x axis), where a comparative example is a structure which doesnot include the wiring overlapping part 233, and an exemplary embodimentmeans a case having the structure of FIG. 2 to FIG. 4.

As shown in FIG. 5, in the comparative example, while the signal istransmitted from the first printed circuit board (PCB) 300 to the firstflexible printed circuit board 200, the impedance value is changed from100Ω to 168Ω such that the difference of the impedance value of 68Ω isgenerated. However, in the exemplary embodiment of FIG. 2 to FIG. 4, theimpedance value is reduced to 130Ω by the parasitic capacitance due tothe wiring overlapping part 233 such that the difference of theimpedance value (i.e., changed value) is reduced to 30Ω.

As a result, the exemplary embodiment of FIG. 2 to FIG. 4 does not reachthe impedance matching in which the impedance difference does not exist.However, the difference of the impedance value is reduced by half ormore compared with the comparative example such that the loss generatedduring the signal transmission due to the impedance difference isreduced. As a result, a merit that the signal transmission performanceis improved may be obtained.

The change in the value of the impedance may be varied depending on thewidth, length (the value g), and structure of the wiring overlappingpart 233.

Next, an electric field characteristic on a cross-sectional view iscompared through FIGS. 6A and 6B.

FIGS. 6A and 6B are views showing an electric field characteristic on across-section of a first flexible printed circuit board according to acomparative example and an exemplary embodiment.

FIG. 6A shows the electric field characteristic on the cross-section inthe comparative example without the wiring overlapping part 233 (i.e.,metal layer), and FIG. 6B shows the electric field characteristic on thecross-section in the exemplary embodiment including the wiringoverlapping part 233 (i.e., metal layer).

Comparing FIG. 6A and FIG. 6B, it may be clearly confirmed that there isa difference in the electric field around the input side wiring 225, andit may be confirmed that the electric field between a pair of input sidewirings 225 is improved in FIG. 6B compared to FIG. 6A, such that thecrosstalk caused by the electric field with other wiring is reduced.

Hereinafter, a route through which the signal is applied from thedisplay device to the data driver 250 is expressed as transmission linesin FIG. 7, and a comparative example and an exemplary embodiment arecompared and described through an eye diagram in the input side of thedata driver 250 in FIGS. 8 and 9.

FIG. 7 is an equivalent circuit diagram for a transmission path of adisplay device according to an exemplary embodiment of FIG. 1, FIG. 8 isan eye diagram in an input side of a data driver according to anexemplary embodiment, and FIG. 9 is an eye diagram in an input side of adata driver according to a comparative example.

First, FIG. 7 is compared with the structure of FIG. 1 and described asfollows.

In FIG. 1, the first printed circuit board (PCB) 300 that is notdirectly connected to the second flexible printed circuit board 410receives the signal outputted from the timing controller 450 through thethird flexible printed circuit board 310 which receives the signal viathe second printed circuit board (PCB) 400, the second flexible printedcircuit board 410, and the adjacent first printed circuit board (PCB)300. Here, a terminal TX connected from the outside to the timingcontroller 450 and a terminal RX outputting the signal from the datadriver 250 to the display panel 100 are additionally disposed toconfigure an equivalent circuit diagram for the transmission line asshown in FIG. 7.

Referring to FIG. 7, the terminal TX connected from the outside to thetiming controller 450 is formed of or includes a pair of wirings totransmit and output the signal, thereby this is shown as a diodeamplifier structure. This is not an illustration of the configuration ofan actual terminal TX, but is simply illustrated as an equivalentcircuit. The terminal TX connected from the outside to the timingcontroller 450 may be disposed on the second printed circuit board (PCB)400.

Next to the terminal TX for input from the outside to the timingcontroller 450, the second printed circuit board (PCB) 400 and thetiming controller 450 are disposed. Here, the characteristicsillustrated as the second printed circuit board (PCB) 400 is the sum ofboth the part that the signal is input to the timing controller 450 andthe part that the signal is output to the timing controller 450.

The second flexible printed circuit board 410 is disposed next to thetiming controller 450. The second flexible printed circuit board 410 isshown by dividing an input terminal 411, an output terminal 412, and awiring part 413 therebetween.

In the subsequent location of the second flexible printed circuit board410, the first printed circuit board (PCB) 300 is disposed, and issimply illustrated. The characteristic of the part to which the secondflexible printed circuit board 410 and the first printed circuit board(PCB) 300 are electrically connected is illustrated as the outputterminal 412 of the second flexible printed circuit board 410.

In the subsequent location of the first printed circuit board (PCB) 300,a third flexible printed circuit board 310 is disposed and isillustrated as including an input terminal 311, an output terminal 312,and a wiring part 313 therebetween. The characteristic of the part towhich the first printed circuit board (PCB) 300 and the third flexibleprinted circuit board 310 are electrically connected is illustrated asthe input terminal 311 of the third flexible printed circuit board 310.

In the subsequent location of the third flexible printed circuit board310, the first printed circuit board (PCB) 300 is disposed, and this isthe first printed circuit board (PCB) 300 that is not directly connectedto the second flexible printed circuit board 410.

In the subsequent location of the first printed circuit board (PCB) 300,the data driver 250 is disposed, and the terminal RX outputting thesignal to the display panel 100 from the data driver 250 is disposed inthe subsequent location of the data driver 250.

The signal characteristic at the input side of the data driver 250 amongthese transmission lines is described as shown in FIG. 8, and forcomparison, a case of a comparative example is shown in FIG. 9.

FIG. 8 and FIG. 9 simulate the high-speed driving signal of 3.4 gigabits(Gbps) in the input terminal of the data driver 250.

FIG. 8 and FIG. 9 show the change of the voltage (millivolts: mV in yaxis) depending on time (picoseconds: ps in x axis), and the values thatare changed while the high-speed driving signal is applied areaccumulated and shown. The rhombus positioned at the center of FIG. 8and FIG. 9 has an eye shape and is called an eye diagram. If there is nopart where the shape of the eye overlaps with the surrounding signalwaveform, it indicates that the display device matches a signalspecification, while if a part among the shape of the eye overlaps thesurrounding signal waveform, the signal specification is not satisfied,and it indicates that an error is generated during the signaltransmission.

FIG. 8 is a simulation diagram for the exemplary embodiment of FIG. 2 toFIG. 4, and a space is formed around the shape of the eye such that itmay be confirmed that even if the high-speed driving signal of 3.4 Gbpsis applied, there is a margin and there is no problem of erroneoustransmission. As a result, it may be predicted that it may be used inhigh-speed driving of higher than 3.4 Gbps (for example, 4 Gbps, or 6Gbps). Particularly, if the impedance difference is reduced by adjustingthe parasitic capacitance that the wiring overlapping part 233 formswith the input side wiring 225, there is no problem of mistransmissioneven in the various high-speed driving.

On the other hand, FIG. 9 is a simulation diagram for the structure ofthe comparative example not including the wiring overlapping part 233,unlike FIG. 2 to FIG. 4, and it may be confirmed that the part of theeye shape is obscured by the waveform when driving at the 3 Gbps highspeed and this is illustrated by the spark shape on the waveform of FIG.9. Therefore, in the comparative example, there is a high possibility ofan error transmission problem when being driven at the high speed of 3.4Gbps, and it may be difficult to be used in the high-speed driving.

Next, numerous variations of exemplary embodiments of the metal tape 230shown in FIG. 2 to FIG. 4 are described.

The cross-sectional structure of the metal tape 230 according to anexemplary embodiment is described through FIG. 10.

FIG. 10 is an enlarged cross-sectional view of a metal tape according toan exemplary embodiment.

The metal tape 230 according to an exemplary embodiment of FIG. 10includes a metal layer 230-M and an adhesive layer 230-2, and areinforcement layer 230-1 and a release layer 230-3 are disposed onrespective sides of the metal layer 230-M as shown in FIG. 10. Thereinforcement layer 230-1 serves to protect the metal tape 230, and isattached by using the adhesive layer 230-2 disposed inside the releaselayer 230-3 after the release layer 230-3 is removed upon attachment.

The metal layer 230-M, the adhesive layer 230-2, and the reinforcementlayer 230-1 of FIG. 10 may be disposed on all of the adhesion part 231,the heat discharge part 232, and the wiring overlapping part 233. Themetal layer 230-M disposed on the heat discharge part 232 plays a mainrole in absorbing and transferring the heat emitted from the data driver250, and the metal layer 203-M disposed on the wiring overlapping part233 transfers the heat, but plays a major role in reducing thedifference in the impedance by generating the parasitic capacitance withthe input side wiring 225. The adhesive layer 230-2 disposed on theadhesion part 231 allows the metal tape 230 to be fixed to the firstflexible printed circuit board 200, and the metal layer 230-M disposedon the adhesion part 231 plays a major role in the heat transferring andreleases the heat to the first flexible printed circuit board 200.

Hereinafter, an integral exemplary embodiment and a separate exemplaryembodiment are described through FIG. 11 and FIG. 12.

FIG. 11 and FIG. 12 are top plan views of a metal tape according to anexemplary embodiment.

The exemplary embodiment of FIG. 11 shows an integral metal tape 230 ofthe same shape as shown in FIG. 2 to FIG. 4.

FIG. 11 shows the metal tape 230 of which the adhesive layer 230-2 andthe metal layer 230-M are disposed together, unlike FIG. 2 to FIG. 4.FIG. 11 shows that the adhesive layer 230-2 has a wider width than themetal layer 230-M in order to be shown in a plan view, but in anexemplary embodiment, they may have outlines that match each other orthe adhesive layer 230-2 may be disposed inside.

The metal layer 230-M includes an adhesion metal layer 231-Mcorresponding to the adhesion part 231, a heat discharge metal layer232-M corresponding to the heat discharge part 232, and a wiringoverlapping metal layer 233-M corresponding to the wiring overlappingpart 233.

On the other hand, in the exemplary embodiment of FIG. 12, unlike theexemplary embodiment of FIG. 11, the wiring overlapping metal layer233-M among the metal layer 230-M has a structure that is separated fromthe heat discharge metal layer 232-M.

The wiring overlapping metal layer 233-M and the heat discharge metallayer 232-M are separated, but have a structure in which they areconnected by the adhesive layer 230-2. An interval d between the wiringoverlapping metal layer 233-M and the heat discharge metal layer 232-Mmay be various according to an exemplary embodiment, and a degree suchthat they are capable of maintaining the connection without separationof the two metal layers by the adhesive layer 230-2 may be provided.

In FIG. 11 and FIG. 12, the adhesive layer 230-2 disposed under themetal layer 230-M is included. According to an exemplary embodiment, theparasitic capacitance between the wiring overlapping part 233 and theinput side wiring 225 may be changed by changing the thickness of theadhesive layer 230-2. That is, the thickness of the adhesive layer 230-2may be increased to reduce the parasitic capacitance, or the thicknessof the adhesive layer 230-2 may be decreased to increase the parasiticcapacitance. The signal transmission ability may be improved by reducingthe impedance difference.

Hereinafter, a linear exemplary embodiment is described through FIG. 13to FIG. 16.

First, the structure of the metal tape of the linear exemplaryembodiment is described with reference to FIG. 13.

FIG. 13 is a top plan view of a first flexible printed circuit board ofa metal tape according to an exemplary embodiment.

In FIG. 13, unlike FIG. 2 to FIG. 4, the metal tape has the structureonly including the wiring overlapping part 233 without including theadhesion part 231 and the heat discharge part 232.

Also, the exemplary embodiment of FIG. 13 shows the structure in whichthe end of the wiring overlapping part 233 matches one side of the inputside pad 220. However, the end of wiring overlapping part 233, as shownin FIG. 2, may be separated from one side of the input side pad 220 ormay overlap the input side pad 220. This is the same in FIG. 14 to FIG.25. The width of the wiring overlapping part 233 may also have theminimum width overlapping only the input side wiring 225.

The metal tape according to the exemplary embodiment of FIG. 13 can beused in a case when it is not necessary to form the heat discharge part232 since the heat discharge of the data driver 250 is easy. Also, theexemplary embodiment of FIG. 13 does not have the part overlapping theoutput side wiring such that there is also a merit that there is noproblem of the signal transmitted to the display panel 100 being delayedby parasitic capacitance.

The linear exemplary embodiment as shown in FIG. 13 may be additionallymodified to have a mesh structure like FIG. 14.

FIG. 14 is a top plan view of a first flexible printed circuit boardincluding a metal tape according to an exemplary embodiment.

In FIG. 14, the wiring overlapping part having the straight shapedefines a plurality of openings of a rhombus structure. Hereinafter,this is also referred to as a mesh structure. Also, in the presentexemplary embodiment, since the mesh structure includes the linearpattern along the outer periphery of the wiring overlapping part233-Mesh, the opening does not have the structure connected to theoutside. However, according to an exemplary embodiment, the shape of theopening may be various, such as circular, and the size and arrangementof the opening may be irregularly defined or the opening may beconnected to the outside. The parasitic capacitance between the wiringoverlapping part 233-Mesh and the input side wiring 225 may be adjustedthrough the area of the opening in the mesh pattern such that theimpedance difference may be controlled by controlling the area.

In addition, in the exemplary embodiment of FIG. 14, the structure inwhich the end of the wiring overlapping part 233-Mesh having the meshpattern coincides with one side of the input side pad 220 is shown.However, the end of the wiring overlapping part 233-Mesh having the meshpattern, as shown in FIG. 2, may be separated from one side of the inputside pad 220.

Hereinafter, an exemplary embodiment additionally that is modified toinclude the adhesive layer 230-2 as shown in FIG. 10 and FIG. 11 isdescribed with reference to FIG. 15 and FIG. 16.

FIG. 15 is a top plan view of a first flexible printed circuit boardincluding a metal tape according to an exemplary embodiment, and FIG. 16is a cross-sectional view taken along line XVI-XVI of FIG. 15.

The exemplary embodiment of FIG. 15 is an exemplary embodiment in whichthe adhesive layer 230-2 is further included in the exemplary embodimentof FIG. 13, the wiring overlapping part 233 is indicated by a thickerline to show the adhesive layer 230-2 in a plan view, and the adhesivelayer 230-2 is marked on the corresponding thick line.

If this is described as a cross-section, it is the same as that of FIG.16, and compared to FIG. 4, the adhesive layer 230-2 is disposed to havethe same width as the wiring overlapping part 233.

That is, the film layer 211, the input side wiring 225, and theinsulating layer 212 configuring the first flexible printed circuitboard 200 are sequentially disposed, and the adhesive layer 230-2 andthe wiring overlapping part 233 configuring the metal tape aresequentially disposed thereon. Next, in FIG. 19, FIG. 22, and FIG. 25,the cross-sectional structure of the adhesive layer 230-2 and the metaltape shown in FIG. 16 is shown by a thick outer line, as in FIG. 15, ina plan view.

Hereinafter, various exemplary embodiments are illustrated withreference to FIG. 17 to FIG. 25.

FIG. 17 to FIG. 25 top plan views of a first flexible printed circuitboard including a metal tape according to an exemplary embodiment.

Among them, FIG. 17 to FIG. 19 show exemplary variations based on thestructure of FIG. 10, FIG. 20 to FIG. 22 show T-shaped exemplaryembodiments, and FIG. 23 to FIG. 25 show plate exemplary embodiments.

First, how the variation of FIG. 13 to FIG. 16 is applied for theexemplary embodiment shown in FIG. 2 to FIG. 4 is described withreference to FIG. 17 to FIG. 19.

FIG. 17 shows the structure of the metal tape 230 corresponding to thestructure of FIG. 2. The structure such as FIG. 2 and FIG. 17 is anexemplary embodiment in which the adhesion part 231 helps the role ofthe heat discharge part 232 such that the characteristic of the heatdischarge is improved. As a result, this is an exemplary embodiment thatmay be used when the need for heat discharge is large.

Unlike FIG. 17, in an exemplary embodiment, the end of the wiringoverlapping part 233 may be separated from one side of the input sidepad 220 or overlap the input side pad 220. Also, the width of the wiringoverlapping part 233 may have the minimum width overlapping only theinput side wiring 225. Also, the exemplary embodiment of FIG. 17 doesnot include the part where the wiring overlapping part 233 and theoutput side wiring are overlapped and only the heat discharge part 232is disposed to minimally overlap the output side wiring. As a result,the problem that the signal transmitted to the display panel 100 isdelayed by the parasitic capacitance does not occur.

An exemplary embodiment in which the mesh structure is further added tothe exemplary embodiment of FIG. 17 is shown in FIG. 18.

The mesh pattern is disposed only in the wiring overlapping part amongthe metal tape 230.

Meanwhile, if it is modified to further include the adhesive layer 230-2in the exemplary embodiment of 17, it becomes the exemplary embodimentshown in FIG. 19. In FIG. 19, the wiring overlapping part 233 is shownby the thicker line to show the adhesive layer 230-2 in a plan view, andthe adhesive layer 230-2 is marked on the corresponding thick line.

Hereinafter, the T-shaped exemplary embodiment and its exemplaryvariations are described with reference to FIG. 20 to FIG. 22.

FIG. 20 shows the T-shape exemplary embodiment, and in this structure,unlike FIG. 2, the heat discharge part 232 and the adhesion part 231 areformed without the width difference, thereby configuring a heatdischarge part 232′. Because the area of the metal tape is large, theheat of the data driver 250 may be discharged more easily, and it may beused when more heat discharge is needed than in the exemplary embodimentof FIG. 2. However, the exemplary embodiment of FIG. 20 may include theheat discharge part 232 shown in FIG. 2 and FIG. 17, and the adhesionpart 231 may be formed narrowly like the width of the heat dischargepart 232 of FIG. 2 and FIG. 17. This case has the effect of preventingthe signal delay by reducing the parasitic capacitance caused with theoutput side wiring instead of letting the heat dissipate in a minimalarea. The impedance matching with the input side wiring 225 may beadjusted by the size of the wiring overlapping part 233.

In an exemplary embodiment, the end of the wiring overlapping part 233,unlike FIG. 2, may be separated from one side of the input side pad 220or overlap the input side pad 220. Also, the width of the wiringoverlapping part 233 may also have the minimum width overlapping onlythe input side wiring 225. Further, the exemplary embodiment of FIG. 20does not include the part where the wiring overlapping part 233 and theoutput side wiring are overlapped, and only the heat discharge part 232is disposed to overlap the output side wiring. There is also apossibility that the signal transmitted to the display panel 100 isdelayed due to the occurrence of the parasitic capacitance due to theoverlap of the heat discharge part 232 and the output side wiring.However, according to an exemplary embodiment, the structure of the heatdischarge part 232 may be changed to implement the heat dischargewithout the delay.

An exemplary embodiment in which the mesh structure is further added tothe exemplary embodiment of FIG. 20 is shown in FIG. 21.

Among the metal tape, the mesh pattern is disposed only on the wiringoverlapping part.

On the other hand, the exemplary embodiment of FIG. 20 is modified tofurther include the adhesive layer 230-2 to become an exemplaryembodiment shown in FIG. 22. FIG. 22 also shows the wiring overlappingpart 233 with the thicker line to show the adhesive layer 230-2 in aplan view, and the adhesive layer 230-2 is marked on the correspondingthick line.

Hereinafter, an exemplary embodiment of a plate type and exemplaryvariations thereof are described with reference to FIG. 23 to FIG. 25.

As shown in FIG. 23, a metal tape 230′ has a quadrangle shape andrespectively has the adhesion part, the heat discharge part, and thewiring overlapping part, but has the structure that is difficult tostructurally distinguish. In the exemplary embodiment of FIG. 23, theheat discharge part may include the periphery part based on the partoverlapping the data driver 250, and the wiring overlapping part mayinclude the periphery part based on the part overlapping the input sidewiring 225. Also, the adhesion part may include the part correspondingto the heat discharge part and the wiring overlapping part, and mayinclude the part that is directly attached to the metal tape 230′ andthe first flexible printed circuit board 200.

In an exemplary embodiment, the end of the wiring overlapping part 233,unlike FIG. 23, may be separated from one side of the input side pad 220or overlap the input side pad 220. Also, the metal tape 230′ overlapsthe output side wiring such that the signal transmitted to the displaypanel 100 may be delayed due the occurrence of the parasiticcapacitance. However, the heat discharge may be realized without thedelay by changing the structure of the heat discharge part 232.

An exemplary embodiment in which the mesh structure is added to theexemplary embodiment of FIG. 23 is shown in FIG. 24. As shown in FIG.24, the wiring overlapping metal layer 233-Mesh having the mesh patternis disposed only at the part overlapping the input side wiring 225 amongthe metal tape 230′. This is to adjust the degree of overlapping of theinput side wiring 225 to control the parasitic capacitance. On the otherhand, an exemplary embodiment of FIG. 25 is provided by modifying theexemplary embodiment of FIG. 23 to further include the adhesive layer230-2. In FIG. 25, the wiring overlapping part 233 is shown with thethicker line to show the adhesive layer 230-2 in a plan view, and theadhesive layer 230-2 is marked on the corresponding thick line.

In addition to the variant exemplary embodiment shown above, variousadditional variant exemplary embodiments are possible. That is, in theexemplary embodiments described above, all are illustrated based on thequadrangle structures, but the structure may be modified based on acircle or polygon. In addition, the size and length of the wiringoverlapping part 233 may be varied, and the shape of the mesh may alsobe varied. The wiring overlapping part 233 and the mesh may be changedso as to reduce the impedance difference or to be matched through theparasitic capacitance with the input side wiring 225.

While this disclosure has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. On the contrary, it is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

<Description of symbols> 100: display panel 110: display area 200, 310,410: flexible printed circuit board 300, 400: printed circuit board(PCB) 250: data driver 450: timing controller 220: input side pad 225:input side wiring 320: pad 325: high-speed driving wiring 230, 230′:metal tape 231: adhesion part 232, 232′: heat discharge part 233,233-Mesh: wiring overlapping part 230-2: adhesive layer 230-M: metallayer 230-1: reinforcement layer 230-3: release layer 231-M: adhesionmetal layer 232-M: heat discharge metal layer 233-M: wiring overlappingmetal 211: film layer layer 212: insulating layer 213: adhesive layer311, 411: input terminal 312, 412: output terminal 313, 413: wiring part

What is claimed is:
 1. A display device comprising: a display panel; adata driver which transmits a data voltage to the display panel; a firstflexible printed circuit board attached to the display panel andincluding an input side wiring electrically connected to the datadriver; a first printed circuit board (PCB) electrically connected tothe input side wiring to transmit a high-speed driving signal to thedata driver; and a metal tape overlapping the input side wiring in aplan view and attached on the first flexible printed circuit board,wherein a part of the metal tape overlapping the input side wiring inthe plan view defines an opening.
 2. The display device of claim 1,wherein the opening is defined in a wiring overlapping part of the metaltape where the metal tape overlaps the input side wiring.
 3. The displaydevice of claim 2, wherein the wiring overlapping part extends from thedata driver toward an input side pad disposed at an end of the inputside wiring.
 4. The display device of claim 3, wherein the metal tapefurther includes a heat discharge part covering the data driver.
 5. Thedisplay device of claim 4, wherein the metal tape further includes anadhesion part which helps attachment on the first flexible printedcircuit board.
 6. The display device of claim 5, wherein a width of theheat discharge part and a width of the adhesion part are different fromeach other.
 7. The display device of claim 5, wherein a width of theheat discharge part and a width of the adhesion part are the same. 8.The display device of claim 5, wherein the metal tape has a platestructure.
 9. The display device of claim 2, wherein the opening isprovided in plural, and the wiring overlapping part further includes alinear structure disposed along an outer periphery of the wiringoverlapping part.
 10. A display device comprising: a display panel; adata driver which transmits a data voltage to the display panel; a firstflexible printed circuit board attached to the display panel andincluding an input side wiring electrically connected to the datadriver; a first printed circuit board (PCB) electrically connected tothe input side wiring and transmitting a high-speed driving signal tothe data driver; and a metal tape overlapping the input side wiring in aplan view and attached on the first flexible printed circuit board,wherein the metal tape includes a heat discharge part overlapping thedata driver in the plan view and disposed in an extending direction ofthe data driver and a wiring overlapping part disposed in a directionperpendicular to the extending direction of the data driver.
 11. Thedisplay device of claim 10, wherein the metal tape includes a metallayer and an adhesive layer, and the adhesive layer is disposed on theentire surface of the metal tape.
 12. The display device of claim 10,wherein the metal tape further includes an adhesion part which helpsattachment on the first flexible printed circuit board, and the heatdischarge part, the wiring overlapping part and the adhesion part areseparated from each other in the plan view.
 13. The display device ofclaim 12, wherein a width of the heat discharge part and a width of theadhesion part are different from each other.
 14. The display device ofclaim 12, wherein a width of the heat discharge part and a width of theadhesion part are the same.
 15. The display device of claim 10, whereinthe wiring overlapping part is separated from an input side pad disposedat an end of the input side wiring by a predetermined distance in theplan view.
 16. The display device of claim 10, wherein the wiringoverlapping part is in contact with the input side pad disposed at anend of the input side wiring in the plan view.
 17. The display device ofclaim 10, wherein the heat discharge part and the wiring overlappingpart are separated with a predetermined interval, and the separated heatdischarge part and wiring overlapping part are connected to each otherby an adhesive contained in the metal tape.
 18. The display device ofclaim 10, wherein the wiring overlapping part defines a plurality ofopenings and includes a linear structure disposed along an outerperiphery of the wiring overlapping part.
 19. The display device ofclaim 10, further comprising: a timing controller which processes animage signal applied from an outside and transmits the processed imagesignal to the data driver; a second printed circuit board (PCB) in whichthe timing controller is disposed; and a second flexible printed circuitboard connecting the second printed circuit board (PCB) and the firstprinted circuit board (PCB).
 20. The display device of claim 19, whereinthe first printed circuit board (PCB) is provided in plural, and thefirst printed circuit boards (PCB) include a first printed circuit board(PCB) connected to the second flexible printed circuit board and a firstprinted circuit board (PCB) which is not connected to the secondflexible printed circuit board, and further comprising: a third flexibleprinted circuit board which connects the first printed circuit board(PCB) which is not connected to the second flexible printed circuitboard and the first printed circuit board (PCB) connected to the secondflexible printed circuit board.